Riceblastfungus, Magnaporthegrisea, produces a series of salicylaldehyde-typephytotoxins such as pyriculol, pyricuol, and pyriculariol. Plausiblebiosyntheticintermediates of these phytotoxins were synthesized in deuterium labeled forms using the Stille coupling reaction as the key step, and subjected to biotransformation by the fungus. Heptatrienylsalicylaldehyde was converted into dihydropyriculol